Climate Change Threatens the Orchids and Ferns That Feed Jungle Water Cycles

In the tropical forests of Monteverde, Costa Rica, branches are carpeted in orchids, ferns, and other epiphytic plants. High in the treetops, these plants suck hydration from low-lying clouds and drip water down to the forest floor, helping the ecosystem retain crucial moisture.

But climate change is drying out the canopy, and epiphytes are dying. Without the epiphytes and their water storage role, the ripple effects throughout the ecosystem could have big impacts on the jungle’s flora and fauna.

In recent years, a team of researchers has been studying climate impacts on the water cycle in Monteverde. Using microclimate sensors and other instruments in the canopy, the researchers are tracking changes in the amount of water moving through the treetops and down to the forest floor, where it supports insect life at the base of the food web, scaling up to feed birds, reptiles, and mammals. The team’s goals include estimating current drought impacts and modeling long-term water availability.

Changing hydrological cycles in Costa Rica are a microcosm of similar threats elsewhere. Dwindling fog, for example, threatens hardwood forests in the Pacific Northwest, and habitats laced with Spanish moss in Georgia. Hence the looming crisis in Monteverde has broader lessons for forests worldwide.

Science journalist Amy McDermott unpacks recent research on shifting water cycles in tropical forests, which are among the most rapid climate impacts to these ecosystems. Filmmaker Noah Kane takes viewers behind the scenes with an accompanying short video, to reveal how the researchers work in the trees.